<template>
  <div class='xtx-carousel' @mouseenter="stop" @mouseleave="start">
    <ul class="carousel-body">
      <li class="carousel-item" v-for="item,i in sliders" :key="item.id" :class="{ fade: index === i }">
        <!-- 轮播图片 -->
        <router-link to="/" v-if="item.imgUrl">
          <img v-lazyload="item.imgUrl" alt="">
        </router-link>

        <!-- 商品列表 -->
        <div v-else class="slider">
          <router-link v-for="goods in item" :key="goods.id" :to="`/product/${goods.id}`">
            <img :src="goods.picture" alt="">
            <p class="name ellipsis">{{ goods.name }}</p>
            <p class="price">&yen;{{ goods.price }}</p>
          </router-link>
        </div>
      </li>
    </ul>
    <a href="javascript:;" class="carousel-btn prev" @click="toggle(-1)"><i class="iconfont icon-angle-left"></i></a>
    <a href="javascript:;" class="carousel-btn next" @click="toggle(1)"><i class="iconfont icon-angle-right"></i></a>
    <div class="carousel-indicator">
      <span v-for="item,i in sliders" :key="item.id" @click="index = i" :class="{ active: index === i}"></span>
    </div>
  </div>
</template>

<script>
import { onUnmounted, ref, watch } from 'vue'

export default {
  name: 'XtxCarousel',
  props: {
    sliders: {
      type: Array,
      default: () => []
    },
    autoPlay: {
      type: Boolean,
      default: false
    },
    intervalTime: {
      type: Number,
      default: 3000
    }
  },

  setup (props) {
    const index = ref(0)

    // 是否自动轮播
    // eslint-disable-next-line no-unused-vars
    let timer = null
    const autoPlayFn = () => {
      // 防止热更新，重复添加定时器
      clearInterval(timer)
      timer = setInterval(() => {
        index.value++
        if (index.value >= props.sliders.length) {
          index.value = 0
        }
      }, props.intervalTime)
    }

    watch(() => props.sliders, (newVlaue) => {
      if (newVlaue.length && props.autoPlay) {
        autoPlayFn()
      }
    }, { immediate: true })

    // 鼠标进入暂停
    const stop = () => {
      if (timer) {
        clearInterval(timer)
      }
    }

    // 鼠标进入开始
    const start = () => {
      if (props.sliders.length && props.autoPlay) {
        autoPlayFn()
      }
    }

    // 点击切换轮播图
    const toggle = (val) => {
      index.value += val
      if (index.value >= props.sliders.length) {
        index.value = 0
        return
      }
      if (index.value < 0) {
        index.value = props.sliders.length - 1
      }
    }

    onUnmounted(() => {
      clearInterval(timer)
    })

    return {
      index, autoPlayFn, stop, start, toggle
    }
  }
}
</script>
<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;

  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }

    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;

      &.fade {
        opacity: 1;
        z-index: 1;
      }

      img {
        width: 100%;
        height: 100%;
      }

      // 轮播商品
      .slider {
        display: flex;
        justify-content: space-around;
        padding: 0 40px;

        >a {
          width: 240px;
          text-align: center;

          img {
            padding: 20px;
            width: 230px !important;
            height: 230px !important;
          }

          .name {
            font-size: 16px;
            color: #666;
            padding: 0 40px;
          }

          .price {
            font-size: 16px;
            color: @priceColor;
            margin-top: 15px;
          }
        }
      }
    }

    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;

      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;

        ~span {
          margin-left: 12px;
        }

        &.active {
          background: #fff;
        }
      }
    }

    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, .2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;

      &.prev {
        left: 20px;
      }

      &.next {
        right: 20px;
      }
    }
  }

  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>
